Plate cylinder holder with slide rail circular bearing assembly

ABSTRACT

A printing machine plate cylinder having a plate tensioning slide rail adjustably mounted within a hollow of the cylinder. The slide rail is supported by a plurality of roller ring modules which stably support the slide rail and permit easy and exact movement of the slide rail in any direction in the adjusting plane.

FIELD OF THE INVENTION

The present invention relates generally to plate cylinders for printingpresses, and more particularly, to plate cylinders having an adjustableslide rail for tensioning a printing plate about the cylinder.

BACKGROUND OF THE INVENTION

Plate cylinders are known which have at least one adjustable slide raildisposed in a hollow or recess of the plate cylinder for tensioning aplate mounted on the cylinder. German patent 3,843,395 discloses aso-called flat pass guide for the adjustment of the slide rail in whicha flat bottomed surface of a slide rail can be moved on the flat top ofa guide. Such known flat pass guides cannot be controlled well,particularly when subjected to forces. For example, a tilting of theslide rail can occur when large forces act upon it. Such slide railsalso often cannot be adjusted in all directions in the plane ofadjustment, which runs parallel to the tangential plane of the platecylinder, but instead are adjustable only in a circumferentialdirection. In other known devices of such type, adjustment in thecircumferential direction makes further adjustment in an axial directionnecessary, since the adjustments in the two mutually perpendiculardirections cannot be completed independently of each other.

OBJECTS AND SUMMARY OF THE PRESENT INVENTION

It is an object of the present invention to provide a printing platecylinder having an improved plate tensioning and adjusting slide railwhich is selectively adjustable in all directions in the adjustingplane.

Another object is to provide a plate cylinder slide rail ascharacterized above which is stably and exactly mountable and can beeasily and accurately moved in the adjusting plane to the desireddegree.

A further object is to provide a printing plate slide rail of the abovekind which is relatively simple in construction and economical inmanufacture.

Other objects and advantages of the invention will become apparent uponreading the following detailed description and upon reference to thedrawings, in which:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partially diagrammatic axial section of a plate cylinderhaving an adjustable slide rail in accordance with the presentinvention;

FIG. 2 is a longitudinal section taken in the plane of line II--II inFIG. 1, showing different positions of a roller ring module unit for theslide rail mounting;

FIG. 3 is a top view of the slide rail shown in FIG. 1; and

FIG. 4 is a fragmentary section taken in the plane of line IV--IV inFIG. 4, showing a motor operated slide rail adjusting means.

While the invention is susceptible of various modifications andalternative constructions, a certain illustrated embodiment thereof hasbeen shown in the drawings and will be described below in detail. Itshould be understood, however, that there is no intention to limit theinvention to the specific form disclosed, but on the contrary, theintention is to cover all modifications, alternative constructions andequivalents falling within the spirit and scope of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now more particularly to the drawings, there is shown aprinting machine plate cylinder 1 having a printing plate 4 mountedthereon. The plate cylinder 1 is formed with a cylindrical hollow orrecess 2, within which a slide rail 3 is mounted. The printing plate 4has one end fastened to the slide rail 3 which is adjustable fortensioning and positioning the plate 4 on the cylinder 1, the pressingstarting point of which is indicated as position 5 in FIG. 1. It will beunderstood by one skilled in the art that the other end of the printingplate may be fastened to a similar slide rail, or alternatively, it maybe held in any suitable conventional manner, for example by springloaded pins which are inserted into holes cut into the end of theprinting plate.

In accordance with the invention, for enabling easy and exact adjustablemovement of the slide rail, the slide rail is supported by at least tworoll bodies of an axial bearing disposed in the adjusting plane of theslide rail. More particularly, the slide rail is supported by aplurality of roll bodies arranged in respective circular cages to formmodular units which permit free movement of the slide rail in alldirections in the adjusting plane. To this end, in the illustratedembodiment, the slide rail 3 is supported for movement by a plurality ofaxially spaced roller ring module units 9 each comprising a plurality ofroll bodies 10, which may be rollers or balls, arranged in a circulararrangement in a circular cage 10a.

In order to support the roller ring modules 9 such that they can followadjustable movement of the slide rail 3 within the printing cylinderhollow 2, each module unit 9 has a respective fastening plate 6 securedto the plate cylinder 1 by screws 14. For enhancing the stability of theslide rail 3 mounting, roller rings modules 9 are disposed on oppositesides of the fastening plate 6 and are retained between upper and lowercover disks, 7, 8, respectively. For retaining the cover disks 7, 8, andthe roller ring modules 9 in assembled relation, a fastening screw 11 ispositionable through respective holes 12 in the cover disks 7, 8 and ahole 13 in the fastening plate 6. The screw 11 threadedly engages atapped hole 15 in the underside of the slide rail 3. The upper coverdisk 7 in this case is supported within a recess in the underside of theslide rail 3, and the slide rail 3, upper cover disc 7, lower cover disc8, and the roller ring modules 9 interposed between the cover discs 7and 8 and the fastening plate 6 all are maintained in assembled relationby the fastening screw 11.

For permitting free movement of the slide rail 3, cover discs 7 and 8,and roller ring modules 9 relative to the fastening plate 6, thefastening plate hole 13 is elongated in a direction transverse to thelongitudinal axis of the slide rail and also is larger than the shank ofthe fastening screw 11 in the longitudinal direction of the slide rail.By such arrangement, it can be seen that pairs of longitudinally spacedroller ring module units 9 can be retained within the hollow 2 of theplate cylinder 1 by a respective fastening plate 6, while permittingfree movement of the slide rail 3 in all directions of the adjustingplane. It will be understood by one skilled in the art that the rollerring module units 9 can be assembled in mounted relation on the sliderail 3 prior to securing the fastening plates 6 to the plate cylinder 1,thereby simplifying assembly and service.

With the slide rail 3 mounted in the hollow 2 of the plate cylinder insuch manner, when forces are applied to the slide rail, it is freelymovable in all possible directions in the adjusting plane II--II, asindicated in FIG. 1 within limits of the hole 13 in the fastening plate6. As depicted in FIG. 2, the shank of the screw 12 is positionablebetween the dotted line positions 11a and 11b as depicted by thepositioning arrow 16, and the roller ring modules 9 are positionable inone direction between the dotted lines 9a and in transverse directionbetween the dotted lines 9b. It will be appreciated that adjustment inthe direction of the arrow 16, as shown in FIGS. 2 and 3 will affectstretching or loosening of the printing plate about the plate cylinderand movement of the slide rail in the direction of the arrow 17 willaffect axial shifting of the slide rail and the printing plate for sideregistration.

In keeping with the invention, to selectively and exactly adjust theslide rail, respective eccentric adjusting means are provided for movingthe slide rail in circumferential and axial directions with respect tothe plate cylinder. For this purpose, the underside of the slide rail 3is formed with a center slot 19 oriented in a circumferential direction,and longitudinal slots 19 parallel to the axis of the cylinder areformed in the underside of the slide rail 3 adjacent its opposite ends.Cross heads 22 are provided in each of the slots 19, 22, the cross headsbeing formed with planes as smooth as possible for movement in the slotsfree from play. As depicted in FIG. 4, the cross heads 22 each havingcenter borings 13 in which pins 24 of eccentrics 25 engage. The pins 24are arranged eccentrically to a cylindrical part 26 of the eccentric 25.The eccentricity illustrated in FIG. 4 by the positioning arrow 27,results from the distance from the center b of a gear 29 to the axis aof the pin 24. By turning the eccentrics 25, therefore, the respectivecross heads 22 can be shifted in slots 19, 20. As a result, the sliderail can be moved in its adjusting plane II--II in each of thecircumferential and axial directions depicted by the arrows 16, 17,respectively, and in all directions in between by virtue of acombination of such eccentric actuated movements.

For rotating each eccentric, a drive motor 28 with a gear 29 may beprovided. Motor operated adjustment may be effected by virtue of asuitable control so that a machine operator can establish the actualpositions of the eccentrics at any time and with it also the actualpositions of the slide rail 3. Alternatively, positioning is possible bymanual adjustment of the eccentrics. As depicted in FIG. 3, the distance30 is the distance between the pressing starting point 5 and a startingor neutral position 31 of the slide rail. Starting from this targetposition, it will be understood by one skilled in the art that thepositions of the slide rail can be calculated and adjusted.

From the foregoing, it can be seen that the slide rail mounting of thepresent invention enables the slide rail to be exactly and stably movedin all directions in the adjusting plane. The slide rail and itsmounting also is relatively simple in construction and economical inmanufacture.

What is claimed is:
 1. A printing machine plate cylinder comprisingmeans for supporting a printing plate about the outer perimeter of thecylinder, means forming a hollow in said cylinder, an elongated sliderail disposed in said hollow, means for securing one end of saidprinting plate to said slide rail, means for supporting said slide railfor selected movement in an adjusting plane substantially parallel to aplane tangent to the plate cylinder at such location, said supportingmeans comprising a plurality of roll bodies for enabling free movementof the slide rail in any direction in the adjusting plane.
 2. The platecylinder of claim 1 in which said roll bodies are disposed atlongitudinally spaced locations along the length of said slide rail. 3.The plate cylinder of claim 2 in which said roll bodies form a modularbearing unit.
 4. The plate cylinder of claim 3 in which said roll bodiesare retained in a circular cage and form a roller ring module.
 5. Theplate cylinder of claim 1 in which said slide rail supporting meansincludes a fastening plate secured to said plate cylinder within saidhollow in a plane parallel to said adjusting plane, and a plurality ofsaid roll bodies disposed on opposite sides of said fastening plate forsupporting said slide rail for movement relative to said fasteningplate.
 6. The plate cylinder of claim 5 including upper and lower coverdisks retaining said roller bodies on opposite sides of said fasteningplate.
 7. The plate cylinder of claim 6 including a fastening screwextending through said cover disks and fastening plate and engaging saidslide rail for retaining said cover disks and roll bodies in assembledrelation on said fastening plate.
 8. The plate cylinder of claim 7 inwhich said fastening plate is formed with an aperture through which saidfastening screw extends, said aperture being larger than said fasteningscrew for permitting relative movement of said slide rail, fasteningscrew, and cover disks with respect to said fastening plate.
 9. Theplate cylinder of claim 4 in which said support means includes aplurality of said roller ring modules disposed at longitudinally spacedlocations along the length of said slide rail.
 10. The plate cylinder ofclaim 1 including a first eccentric rotatably supported by said platecylinder and engaging an underside of said slide rail, said firsteccentric being rotatable for moving said slide rail in the adjustingplane in . .a circumferential.!. .Iadd.an axial .Iaddend.direction withrespect to said plate cylinder, a second eccentric, said secondeccentric being rotatably supported by said plate cylinder andengageable with said slide rail, and said second eccentric beingrotatable to move said . .plate cylinder.!. .Iadd.slide rail .Iaddend.in. .an axial.!. .Iadd.a circumferential .Iaddend.direction with respectto said plate cylinder.
 11. The plate cylinder of claim 10 in which saidfirst eccentric engages an underside of the slide rail at the centerthereof, and including a pair of said second eccentrics each engaging anunderside of the slide rail at a location adjacent a respective endthereof.
 12. The plate cylinder of claim 10 in which said slide rail isformed with a transverse slot on an underside thereof extending in thecircumferential direction with respect to the plate cylinder, a firstcross head disposed within said transverse slot for relative movementtherein, said first eccentric includes a pin that engages said firstcross head and which moves said cross head in said slot in response torotational movement of said first eccentric, said side rail being formedwith a second slot disposed in a longitudinal direction parallel to theaxis of said plate cylinder, a second cross head disposed in said secondslot for movement therein, and said second eccentric including a pinengaged with said second cross head for moving said second cross head insaid second slot in response to rotational movement of said secondeccentric.
 13. The plate cylinder of claim 12 including motor means forrotating said first and second eccentrics. .Iadd.
 14. A printingcylinder supporting a printing plate on an outer surface thereof, theprinting cylinder comprising:a recess formed in the printing cylinder; aslide rail disposed in the recess; a printing plate holding device forsecuring one end of the printing plate to the slide rail; at least onefirst eccentric rotatably supported on the printing cylinder andengaging the slide rail, the at least one first eccentric beingrotatable for moving the slide rail in a circumferential directionrelative to the printing cylinder; and at least one second eccentricrotatably supported on the printing cylinder and engaging the sliderail, the at least one second eccentric being rotatable to move theslide rail in an axial direction relative to the printingcylinder..Iaddend..Iadd.15. The printing cylinder of claim 14, whereinthe at least one first eccentric is located at a central portion of theslide rail..Iaddend..Iadd.16. The printing cylinder of claim 14, whereinthe at least one second eccentric is located at an end portion of theslide rail..Iaddend..Iadd.17. The printing cylinder of claim 14, furthercomprising an additional second eccentric rotatably supported on theprinting cylinder and engaging the slide rail, the additional secondeccentric being rotatable to move the slide rail in an axial directionrelative to the printing cylinder..Iaddend..Iadd.18. The printingcylinder of claim 17, wherein the additional second eccentric is locatedat one end portion of the slide rail and the at least one secondeccentric is located at an opposite end portion of the sliderail..Iaddend..Iadd.19. The printing cylinder of claim 18, wherein theat least one first eccentric is disposed between the at least one secondeccentric and the additional second eccentric..Iaddend..Iadd.20. Theprinting cylinder of claim 14, wherein the at least one first eccentricand the at least one second eccentric are arranged to engage anunderside of the slide rail..Iaddend.